NOTES: Other includes "flyaway aircraft" (i.e., aircraft moving from
the manufacturer to a customer and not carrying any freight), vessels moving
under their own power, pedestrians carrying freight, and miscellaneous. Shipments
that neither originate nor terminate in the United States (i.e., in-transit
shipments) are not included here, although they use the U.S. transportation
system. These shipments are usually part of Mexico-Canada trade and simply pass
through the United States. Merchandise trade data exclude export shipments valued
at less than $2,500 and import shipments valued at less than $1,250. Individual
modal totals may not sum to exact export or import totals due to rounding.

SOURCES: U.S. Department of Transportation, Bureau of Transportation Statistics,
special tabulation, May 2002; based on: total trade, air, and water-U.S.
Department of Commerce, U.S. Census Bureau, Foreign Trade Division, FT920
U.S. Merchandise Trade (Washington, DC: 2001); all land modes-U.S.
Department of Transportation, Bureau of Transportation Statistics, Transborder
Surface Freight Data, January 2002.